This invention relates to plant protecting compositions containing adjuvant compositions, and in particular, to adjuvant compositions that contain a topped or peaked alcohol ethoxylate or combinations thereof in combination with a conventional alcohol ethoxylate.
Adjuvants are commonly used in plant protecting compositions to facilitate biocidal action or to facilitate or modify characteristics of the biocidal formulations or spray solutions. In order to enhance or modify the chemical and/or physical characteristics of certain pesticides, adjuvants are added to form a mixture for spraying. Since spray application can be critical to the performance of the agricultural chemical, adjuvants are added to reduce application problems such as chemical stability, incompatibility, solubility, suspension, foaming, drift, evaporation, volatilization, phytotoxicity, surface tension, droplet size and coverage. They can, depending on their type, enhance wetting, translocation, spreading, sticking, emulsifying, dispersing and biological activity. Adjuvants include wetting agents, crop oil concentrates, spreaders, stickers, buffering agents, foaming and anti-foaming agents, dispersing agents and drift control agents. Over 200 EPA-registered pesticides have specific recommendations on their labels for adjuvant use. For example, they are recommended to enhance biological activity of the pesticide and to reduce, minimize or eliminate spray application problems as previously noted. There are several different types of adjuvants recommended. To achieve consistent and effective results, the user must first select the desired type of adjuvant and then the appropriate product within that specific type for use with a particular biocide and then use that product at recommended rates. Adjuvants can be added to the biocide formulation (commonly called "ready-to-dilute") or at the applicator stage when the pesticide formulation is diluted with water or a suitable carrier into a spray tank (commonly called "tank mix").
Nonionic surfactants have been used as activator adjuvants to facilitate biocide penetration wetting, spreading, dispersing, solubilizing, emulsifying and other surface modifying properties to bring about enhanced biocidal action. These surfactants have also been used as spray-modifier adjuvants to facilitate sticking or spreading of wettable biocidal powders or to modify the drift properties of the biocide. Examples of common nonionic surfactants used as spray adjuvants can be found in Adjuvants for Herbicides (Weed Science Society of America 1982), which is incorporated herein by reference.
A common nonionic surfactant used as an adjuvant is an alkyl aryl oxylate such as nonyl ethoxylate phenol, also known as nonoxynol-10. Although nonoxynol-10 is effective, suitable alternatives are continually being sought.
An acceptable alternative is a conventional aliphatic alcohol alkoxylate, commonly called an alcohol alkoxylate, such as alcohol ethoxylates. Alcohol ethoxylates or ethylene oxide adducts are nonionic surfactants having functional properties such as wetting, foaming, emulsifying, and dispersing abilities as well as solubilization and detergent abilities. While the use of alcohol ethoxylates alone as adjuvants has been satisfactory, there is an ongoing effort to make adjuvants with improved herbicidal performance.
Surprisingly, it has been found that the addition of an adjuvant composition containing topped or peaked alcohol alkoxylates, or combinations thereof in combination with conventional alcohol alkoxylates to certain post emergent biocidal mixtures increases the efficacy of these biocides beyond that of recognized standards.